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Abstract:

A vehicle wiper assembly includes a wiper blade configured to wipe a
surface, an armature, and an actuator. The armature has a first end
spaced from a second end, and is coupled with the wiper blade at the
first end, and coupled to a pivot mechanism at the second end. The pivot
mechanism is configured to allow the wiper blade to articulate about the
second end in a direction substantially away from the surface and between
a wiping position and a parked position. The actuator is provided in
mechanical communication with the armature and is configured to receive
an electrical actuation signal to transition the wiper blade between a
wiping position and the parked position, where the wiper blade is in
contact with the surface while in the wiping position, and is separated
from the surface while in the parked position.

Claims:

1. A vehicle wiper assembly comprising: a wiper blade configured to wipe
a surface; an armature including a first end spaced from a second end,
the armature coupled with the wiper blade at the first end, and coupled
to a pivot mechanism at the second end, the pivot mechanism configured to
allow the wiper blade and armature to articulate about the second end in
a direction substantially away from the surface and between a wiping
position and a parked position; and an actuator in mechanical
communication with the armature and configured to receive an electrical
actuation signal; wherein the wiper blade is in contact with the surface
while in the wiping position, and the wiper blade is separated from the
surface while in the parked position; and wherein the actuator is
configured to transition the wiper blade between the wiping position and
the parked position in response to the received electrical actuation
signal.

2. The vehicle wiper assembly of claim 1, wherein the actuator includes a
shape memory alloy material having a crystallographic phase that is
changeable between martensite and austenite in response to the electrical
actuation signal.

3. The vehicle wiper assembly of claim 2, wherein the shape memory alloy
material is a wire having a length, the wire being configured to contract
in length in response to the electrical actuation signal.

4. The vehicle wiper assembly of claim 3, wherein the wire is in
mechanical communication with the armature; and wherein a contraction of
the length of the wire is operatively configured to transition the
armature to articulate about the second end.

5. The vehicle wiper assembly of claim 1, wherein the actuator includes
an extendable riser disposed between the armature and the surface, the
riser having a height that is transitionable between a nominal position
and an extended position in response to the electrical actuation signal;
and wherein the extendable riser is operative to lift a portion of the
armature when transitioned to the extended position.

6. The vehicle wiper assembly of claim 1, wherein the actuator includes
an articulating stand disposed between the armature and the surface, the
stand configured to articulate between a collapsed position and a
standing position in response to the electrical actuation signal; and
wherein the stand is operative to lift a portion of the armature when
articulated to the standing position.

7. The vehicle wiper assembly of claim 1, further comprising a rotary hub
coupled to the second end of the armature, the rotary hub having an axis
of rotation and configured to articulate the wiper blade about the second
end and in a direction substantially along the surface.

8. The vehicle wiper assembly of claim 7, wherein the actuator includes
the rotary hub, the rotary hub being configured to translate along the
axis of rotation to transition the wiper blade between the wiping
position and the parked position.

9. The vehicle wiper assembly of claim 1, further comprising a controller
configured to provide the electrical actuation signal.

10. The vehicle wiper assembly of claim 1, wherein the pivot mechanism is
configured to selectively maintain the wiper blade in the parked
position.

11. The vehicle wiper assembly of claim 1, further comprising a return
mechanism configured to apply a force to the armature that urges the
armature to rotate about the pivot mechanism in a direction toward the
surface.

12. The vehicle wiper assembly of claim 11, wherein the force applied to
the armature by the return mechanism is operative to cause the wiper
blade to strike the surface.

13. A vehicle wiper assembly comprising: a wiper blade configured to wipe
a surface; an armature including a first end spaced from a second end,
the armature coupled with the wiper blade at the first end, and coupled
to a pivot mechanism at the second end, the pivot mechanism configured to
allow the wiper blade and armature to articulate about the second end in
a direction substantially away from the surface and between a wiping
position and a parked position; and an actuator in mechanical
communication with the armature and configured to receive an electrical
actuation signal, the actuator including a shape memory alloy material
having a crystallographic phase that is changeable between martensite and
austenite in response to the electrical actuation signal; wherein the
wiper blade is in contact with the surface while in the wiping position,
and the wiper blade is separated from the surface while in the parked
position; and wherein the shape memory alloy material has a length that
is operatively configured to contract in response to the electrical
actuation signal, and wherein the contraction in length is operatively
configured to transition the wiper blade between the wiping position and
the parked position.

14. The vehicle wiper assembly of claim 13, wherein the actuator includes
an extendable riser disposed between the armature and the surface, the
riser having a height that is transitionable between a nominal position
and an extended position in response to the contraction in length of the
shape memory alloy material; and wherein the extendable riser is
operative to lift a portion of the armature when transitioned to the
extended position.

15. The vehicle wiper assembly of claim 13, wherein the actuator includes
an articulating stand disposed between the armature and the surface, the
stand and configured to articulate between a collapsed position and a
standing position in response to the contraction in length of the shape
memory alloy material; and wherein the stand is operative to lift a
portion of the armature when articulated to the standing position.

16. The vehicle wiper assembly of claim 13, further comprising a rotary
hub coupled to the second end of the armature, the rotary hub having an
axis of rotation and configured to articulate the wiper blade about the
second end and in a direction substantially along the surface.

17. The vehicle wiper assembly of claim 16, wherein the actuator includes
the rotary hub, the rotary hub being configured to translate along the
axis of rotation in response to the contraction in length of the shape
memory alloy material, the translation configured to transition the wiper
blade between the wiping position and the parked position.

18. The vehicle wiper assembly of claim 13, further comprising a
controller configured to provide the electrical actuation signal in
response to an event signal.

19. The vehicle wiper assembly of claim 13, wherein the pivot mechanism
includes a locking mechanism configured to selectively maintain the wiper
blade in the parked position.

20. A vehicle wiper assembly comprising: a wiper blade configured to wipe
a surface; an armature including a first end spaced from a second end,
the armature coupled with the wiper blade at the first end, and coupled
to a pivot mechanism at the second end, the pivot mechanism configured to
allow the wiper blade and armature to articulate about the second end in
a direction substantially away from the surface and between a wiping
position and a parked position; a controller configured to provide an
electrical actuation signal in response to an event signal, the event
signal indicative of a depressed button, a toggled switch, a turned dial,
or an ignition key in an "off" position. an actuator in mechanical
communication with the armature and configured to receive the electrical
actuation signal, the actuator being configured to transition the wiper
blade between the wiping position and the parked position in response to
the received electrical actuation signal; and wherein the wiper blade is
in contact with the surface while in the wiping position, and the wiper
blade is separated from the surface while in the parked position.

Description:

[0002] A vehicle wiper assembly is a device used to remove liquid, such as
rain, and/or debris from the surface of a vehicle window. Often wiper
assemblies are used in conjunction with the front windshield/windscreen
of the vehicle and/or a rear window of the vehicle. Vehicles that may
employ the use of wiper assemblies may include, for example, automobiles,
trains, aircrafts and watercrafts.

[0003] A wiper assembly may generally include a long wiper blade that is
swung back and forth over the surface of the glass to push water from its
surface. The speed is normally adjustable, with several continuous speeds
and often one or more "intermittent" settings. Also, the blade may be
adapted to conform to any varying curvature that may be present along the
surface of the window.

[0004] During inclement weather, especially in colder climates, rain or
melted snow may accumulate on the wiper blade, where it may freeze to
ice. Accumulated ice may detract from the blade's ability to conform to a
varying surface curvature or wiping ability. Additionally, the wiper
blade may freeze to the surface of the window if left in stationary
contact with the surface during, for example, a snow storm. Removing the
blade from its frozen condition may tend to cause damage to the blade,
which may result in reduced wiping performance.

SUMMARY

[0005] A vehicle wiper assembly includes a wiper blade configured to wipe
a surface, an armature, and an actuator. The armature has a first end
spaced from a second end, and is coupled with the wiper blade at the
first end, and coupled to a pivot mechanism at the second end. The pivot
mechanism is configured to allow the wiper blade to articulate about the
second end in a direction substantially away from the surface and between
a wiping position and a parked position. The actuator is provided in
mechanical communication with the armature and is configured to receive
an electrical actuation signal that transitions the wiper blade between a
wiping position and the parked position, wherein the wiper blade is in
contact with the surface while in the wiping position, and is separated
from the surface while in the parked position.

[0006] In an embodiment, the actuator may include a shape memory alloy
material having a crystallographic phase that is changeable between
austenite and martensite in response to the electrical actuation signal.
For example, the shape memory alloy material may be formed into a wire
that has a length, where the wire is configured to contract in length in
response to the electrical actuation signal. The wire may be in
mechanical communication with the armature, and the contraction of the
length of the wire may be configured to urge the armature to articulate
about the second end.

[0007] In one configuration, the actuator may include an extendable riser
disposed between the armature and the surface, wherein the riser has a
height that is transitionable between a nominal position and an extended
position in response to the electrical actuation signal. As such, the
extendable riser may be operative to lift a portion of the armature when
transitioned to the extended position.

[0008] In another configuration, the actuator may include an articulating
stand disposed between the armature and the surface. The stand may be
configured to articulate between a collapsed position and a standing
position in response to the electrical actuation signal, where it is
operative to lift a portion of the armature when articulated to the
standing position.

[0009] In yet another configuration, the vehicle wiper assembly may
further include a rotary hub coupled to the second end of the armature.
The rotary hub may have an axis of rotation and be configured to
articulate the wiper blade about the second end and in a direction
substantially along the surface. The actuator may include the rotary hub,
where the rotary hub is additionally configured to translate along the
axis of rotation to transition the wiper blade between the wiping
position and the parked position.

[0010] The vehicle wiper assembly may include a controller that is
configured to provide the electrical actuation signal to the actuator in
response to a key-off event or a user event. Additionally, the pivot
mechanism may include a locking mechanism that is configured to
selectively maintain the wiper blade in the parked position.

[0011] The above features and advantages and other features and advantages
of the present invention are readily apparent from the following detailed
description of the best modes for carrying out the invention when taken
in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is a perspective illustration of a vehicle wiper assembly
disposed in a wiping position in contact with a surface.

[0013] FIG. 2 is a perspective illustration of a vehicle wiper assembly
disposed in a parked position separate from the surface.

[0014] FIG. 3 is a schematic side view of an embodiment of a vehicle wiper
assembly including a tendon-type actuator.

[0015] FIG. 4 is a schematic side view of an embodiment of a vehicle wiper
assembly including a selectively extendable riser.

[0016] FIG. 5 is a schematic side view of an embodiment of a vehicle wiper
assembly including a selectively articulating stand.

[0017] FIG. 6 is a schematic side view of an embodiment of a vehicle wiper
assembly including a selectively translatable rotary hub.

DETAILED DESCRIPTION

[0018] Referring to the drawings, wherein like reference numerals are used
to identify like or identical components in the various views, FIG. 1
schematically illustrates a vehicle 10 having a pair of wiper assemblies
12 configured to wipe a liquid across the surface 14 of a window.

[0019] Each wiper assembly 12 may include an armature 16 that may be
coupled to a wiper blade 18 at a first end 20 and coupled to a rotary hub
22 at a second end 24. The rotary hub 22 may have an axis of rotation
that is substantially normal to the surface 14, and may be configured to
articulate the wiper blade 18 along the surface 14 in an arc-shaped path
26. Such a motion may, for example, allow the wiper blade 18 to push
liquid or debris toward the perimeter of the surface 14 of the window.

[0020] The armature 16 may further include a pivot mechanism 28 coupled to
the second end 24, which may allow the armature 16 and wiper blade 18 to
articulate in a direction 30 substantially away from the surface 14 as
generally illustrated in FIG. 2. Such an articulation may be generally
made about the second end 24, and may transition the wiper blade 18
between a wiping position (generally illustrated at 40 in FIG. 1) and a
parked position (generally illustrated at 42 in FIG. 2). The pivot
mechanism 28 may additionally be configured to selectively hold and/or
maintain the wiper blade 18 in either the parked 42 or wiping 40
position, such as through the use of detents, latches, or other similar
holding/locking means. For example, a spring may be used to hold the
wiper blade 18 in the wiping position 40. While in the wiping position
40, the wiper blade 18 may generally be in contact with the surface 14
along its entire length. Thus, motion along the arc-shaped path 26 while
the wiper blade 18 is in the wiping position 40 may be effective to clear
liquid or debris from the surface 14. Conversely, while the wiper blade
18 is in the parked position 42, the wiper blade 18 may be substantially
separated, or positioned apart from the surface 14. As further
illustrated in FIG. 2, to lift and/or maintain the armature 16 and wiper
blade 18 in the parked position, a stand 44 may extend between the
surface 14 and the armature 16.

[0021] When parking the vehicle in cold, wet weather conditions,
separating the wiper blade 18 from the surface 14 (i.e., in the parked
position 42), may prevent the blade 18 from freezing to the surface 14.
Similarly, when in hot weather conditions, the parked position 42 may
prevent the blade 18 from permanently deforming against the surface 14
such as when the blade 18 may be softened from the heat.

[0022] As generally illustrated in FIGS. 3-6, an actuator 50 may be in
mechanical communication with the armature 16, and may be configured to
transition the wiper blade 18 between the wiping position 40 and the
parked position 42. The actuator 50 may be configured to receive an
electrical actuation signal 52 from a controller 54, and transition the
wiper blade 18 in response to the signal 52. While the actuator 50 may
take various forms, in one configuration, it may include a shape memory
alloy material 56 with a crystallographic phase that is changeable
between austenite and martensite in response to the electrical actuation
signal 52.

[0023] As used herein, the terminology "shape memory alloy" (often
abbreviated as "SMA") refers to alloys which exhibit a shape memory
effect. That is, the shape memory alloy material 56 may undergo a solid
state, crystallographic phase change to shift between a martensite phase,
i.e., "martensite", and an austenite phase, i.e., "austenite."
Alternatively stated, the shape memory alloy material 56 may undergo a
displacive transformation rather than a diffusional transformation to
shift between martensite and austenite. A displacive transformation is a
structural change that occurs by the coordinated movement of atoms (or
groups of atoms) relative to their neighbors. In general, the martensite
phase refers to the comparatively lower-temperature phase and is often
more deformable than the comparatively higher-temperature austenite
phase.

[0024] The temperature at which the shape memory alloy material 56 begins
to change from the austenite phase to the martensite phase is known as
the martensite start temperature, Ms. The temperature at which the
shape memory alloy material 56 completes the change from the austenite
phase to the martensite phase is known as the martensite finish
temperature, Mf. Similarly, as the shape memory alloy material 56 is
heated, the temperature at which the shape memory alloy material 56
begins to change from the martensite phase to the austenite phase is
known as the austenite start temperature, As. The temperature at
which the shape memory alloy material 56 completes the change from the
martensite phase to the austenite phase is known as the austenite finish
temperature, Af.

[0025] Therefore, the shape memory alloy material 56 may be characterized
by a cold state, i.e., when a temperature of the shape memory alloy
material 56 is below the martensite finish temperature Mf of the
shape memory alloy material 56. Likewise, the shape memory alloy material
56 may also be characterized by a hot state, i.e., when the temperature
of the shape memory alloy material 56 is above the austenite finish
temperature Af of the shape memory alloy material 56.

[0026] In operation, shape memory alloy material 56 that is pre-strained
or subjected to tensile stress can change dimension upon changing
crystallographic phase to thereby convert thermal energy to mechanical
energy. That is, the shape memory alloy material 56 may change
crystallographic phase from martensite to austenite and thereby
dimensionally contract if pseudoplastically pre-strained so as to convert
thermal energy to mechanical energy. Conversely, the shape memory alloy
material 56 may change crystallographic phase from austenite to
martensite and if under stress thereby dimensionally expand so as to also
convert thermal energy to mechanical energy.

[0027] Pseudoplastically pre-strained refers to stretching of the shape
memory alloy material 56 while in the martensite phase so that the strain
exhibited by the shape memory alloy material 56 under that loading
condition is not fully recovered when unloaded, where purely elastic
strain would be fully recovered. In the case of the shape memory alloy
material 56, it is possible to load the material such that the elastic
strain limit is surpassed and deformation takes place in the martensitic
crystal structure of the material prior to exceeding the true plastic
strain limit of the material. Strain of this type, between those two
limits, is pseudoplastic strain, called such because upon unloading it
appears to have plastically deformed. However, when heated to the point
that the shape memory alloy material 56 transforms to its austenite
phase, that strain can be recovered, returning the shape memory alloy
material 56 to the original length observed prior to application of the
load.

[0028] The shape memory alloy material 56 may be stretched before
installation into the actuator 50, such that a nominal length of the
shape memory alloy material 56 includes recoverable pseudoplastic strain.
Alternating between the pseudoplastic deformation state (relatively long
length) and the fully-recovered austenite phase (relatively short length)
may apply a force that may be used to lift the wiper blade 18.

[0029] The shape memory alloy material 56 may change both modulus and
dimension upon changing crystallographic phase to thereby convert thermal
energy to mechanical energy. More specifically, the shape memory alloy
material 56, if pseudoplastically pre-strained, may dimensionally
contract upon changing crystallographic phase from martensite to
austenite and may dimensionally expand, if under tensile stress, upon
changing crystallographic phase from austenite to martensite to thereby
convert thermal energy to mechanical energy. Therefore, if the shape
memory alloy material 56 is resistively heated via an electrical
actuation signal 52, it may dimensionally contract upon changing
crystallographic phase between martensite and austenite.

[0031] The shape memory alloy material 56 can be binary, ternary, or any
higher order so long as the shape memory alloy material 56 exhibits a
shape memory effect, i.e., a change in shape orientation, damping
capacity, and the like. The specific shape memory alloy material 56 may
be selected according to expected operating temperatures that the wiper
assembly 12 will be used with. In one specific example, the shape memory
alloy material 56 may include nickel and titanium.

[0032] In other embodiments, the actuator 50 may include motors,
solenoids, or other actuation means that may be responsive to an
electrical actuation signal 52. While FIGS. 3-6 illustrate various types
of actuators, these embodiments should be regarded as illustrative rather
than exclusive. As may be appreciated, the shape memory alloy material 56
may be suitably replaced with other linear actuation means.
Alternatively, the pivot mechanism 28 may be directly coupled to and/or
include various direct drive motors, geared motors, or other similar
drive mechanisms.

[0033] In an embodiment, the wiper assembly 12 may further include a
return mechanism 58 that may be configured to transition the blade 18
from the parked position 42 to the wiping position 40. The return
mechanism 58 may include, for example, a spring or an actuator that may
apply a force to the armature 16 in such a manner to rotate the armature
16 and wiper blade 18 about the pivot mechanism 28 in a direction toward
the surface 14. In one configuration, the return mechanism 58 may be
configured to provide a gradual return force to controllably return the
assembly 12 to the wiping position 40. In another configuration, the
return mechanism 58 may apply a strong enough force for debris or ice to
be knocked loose of the wiper blade 18 when the blade 18 strikes the
surface 14. As such, the parking mechanism may be used as a de-icing
apparatus.

[0034] Referring specifically to FIG. 3, a wiper assembly 12 is
schematically illustrated, where the wiper assembly 12 includes a wiper
blade 18 coupled with a first end 20 of an armature 16. The armature 16
may further include a pivot mechanism 28 coupled at the second end 24.
FIG. 3 illustrates the wiper assembly 12 disposed in a parked position
42, though having been transitioned in a direction 30 substantially away
from the surface 14, from a wiping position 40.

[0035] As schematically illustrated in FIG. 3 the actuator 50 may include
a shape memory alloy material 56 that is disposed across the pivot
mechanism 28 in a tendon-like arrangement. In one configuration, the
shape memory alloy material 56 may be coupled to a riser 60 that may
extend from the armature to enhance the mechanical leverage of the
actuator 50. In another embodiment, a second riser may similarly be
disposed on the opposing side of the pivot mechanism 28 to further
increase the mechanical leverage of the actuator 50.

[0036] The shape memory alloy material 56 may be formed as a wire, which
has a length configured to contract in response to an electrical
actuation signal 52. In one configuration, the electrical actuation
signal 52 may be provided by a controller 54 that may be in electrical
communication with the actuator 50. As such, the wire may be
pseudoplastically pre-stretched while in a martensite phase, with the
wiper assembly 12 in a wiping position 40. Upon receipt of the electrical
actuation signal 52, the phase of the shape memory alloy material 56 may
change to austenite, wherein the pseudoplastic strain may be recovered.
The reduction in the length of the shape memory alloy material 56 may
correspondingly urge the armature 16 to articulate about the second end
24 (i.e., the pivot mechanism 28). As may be appreciated, the
articulation of the armature 16 may transition the wiper blade 18 between
the wiping position 40 in contact with the surface 14, and the parked
position 42 separate from the surface 14.

[0037] FIG. 4 is a schematic illustration of a wiper assembly 12 that
includes an actuator 50 configured to lift a portion of the armature 16.
As shown, the actuator 50 may be disposed between the surface 14 and the
armature 16, and may include an extendable riser 70 adapted to
mechanically engage and apply a lifting force to the armature 16. In one
configuration, the riser 70 may selectively transition between a nominal
position 72 and an extended position 74. In the nominal position 72, for
example, the riser 70 may be generally situated apart from the armature
16 and/or in a configuration where the riser 70 applies substantially no
upward lifting force to the armature 16. In the extended position 74, the
riser 70 may extend upward from the surface 14 to such a degree where it
may hold the armature 16 and wiper blade 18 in a parked position 42.

[0038] The actuator 50 may be configured to transition between the nominal
position 72 and the extended position 74 in response to an electrical
actuation signal 52, such as one provided by a controller 54. During the
transition, the riser 70 may mechanically engage the armature 16, and may
further urge it to articulate away from the surface 14 and about the
second end 24. In one embodiment, the actuator 50 may include, for
example, one or more actuator elements that may each comprise a
respective shape memory alloy material 56. In another embodiment, the
actuator 50 may include one or more other linear-type actuators, such as,
for example, solenoids, rack and pinion mechanisms, linear screws,
electrically controlled pneumatics or hydraulics, or other similarly
situated actuators.

[0039] As schematically illustrated, the shape memory alloy material 56
may be disposed between the riser 70 and the surface 14. In such an
embodiment, the shape memory alloy material 56 may be pseudoplastically
pre-strained and configured to contract in length when transitioned into
an austenite phase (e.g., when it is resistively heated by the electrical
actuation signal 52). As may be appreciated, other similar configurations
may be employed to enable the riser 70 to extend from the surface 14 in
response to the electrical actuation signal 52.

[0040] FIG. 5 schematically illustrates an embodiment of a windshield
wiper assembly 12, where the actuator 50 includes an articulating stand
80 disposed between the armature 16 and the surface 14. The stand 80 may
be configured to articulate between a collapsed position 82 (i.e.,
substantially parallel with the surface), and a standing position 84,
where the stand 80 may be operative to lift a portion of the armature 16
when articulated to the standing position 84 (as shown). The stand 80 may
transition between the collapsed position 82 and the standing position 84
in response to an electrical actuation signal 52 that may be provided
from a controller 54.

[0041] In one configuration, the actuator 50 may include a shape memory
alloy material 56 that may be coupled between, for example, a riser 86
and the articulating stand 80. The shape memory alloy material 56 may be
pseudoplastically pre-strained while in the collapsed position 82,
however, may recover that strain and contract in length when transitioned
to an austenite phase (e.g., through resistive heating). In other
configurations, other rotary or linear actuators may be used to
transition the stand 80 between the collapsed position 82 and the
standing position 84. For example, a motor may be coupled to the central
hub of the articulating stand 80, either directly, or through one or more
gears, belts, or pulleys, to selectively articulate the state 80. When
transitioned to a standing position 84, the stand 80 may mechanically
contact the armature 16, and urge it to pivot away from the surface 14.

[0042] While FIGS. 4 and 5 schematically illustrate the actuator 50
positioned on the surface 14 and configured to extend up to the armature
16, it is equally possible to position the actuator 50 on the armature
16, where it would be configured to extend down to contact the surface 14
and apply the lifting force.

[0043] FIG. 6 schematically illustrates an embodiment of a wiper assembly
12 that integrates the actuator 50 with the rotary hub 22 that may
articulate the wiper blade 18 along the surface 14 in an arc-shaped path
26 (as generally described above with reference to FIG. 1). As
schematically illustrated, the rotary hub 22 may be configured to impart
a rotary motion 90 to a drive axle 92 which may be directly joined to the
armature 16. The drive axle 92 may be disposed within a drive means 94
that is configured to impart the rotary motion 90 to the axle 92 about an
axis of rotation 96. In one embodiment, the drive axle 92 may be a rotor
disposed within a stator. In other embodiments, however, various cam
mechanisms and/or linkages may alternatively or additionally be employed
as the drive means 94 to articulate the drive axle 92.

[0044] As generally provided in FIG. 6, the drive axle 92 may be
configured to translate within the drive means 94 and along the axis of
rotation 96. This translation may generally be made between a first
position 98 and a second position 100. As the drive axle 92 translates,
it may be rigidly coupled with the armature 16 such that the armature 16
will correspondingly translate along the axis of rotation 96, which may
be normal to the surface 14. A downward/inward translation of the
armature 16 relative to the surface may then cause the armature 16 to
pivot about a riser 102, which may extend from the surface 14. Similarly,
the actuation may cause a corresponding pivot motion about the pivot
mechanism 28.

[0045] The translation of the drive axle 92 may be caused by the actuator
50, which may include, for example, a shape memory alloy material 56
responsive to an electrical actuation signal 52 provided by a controller
54. In other configurations, the actuator 50 may include other types of
liner actuators, including, for example, solenoids, rack and pinion
mechanisms, linear screws, electrically controlled pneumatics or
hydraulics, or other similarly situated actuators. As may be appreciated,
translation of the drive axle 92, and the corresponding pivoting motion,
may be operative to transition the wiper blade between the wiping
position (not shown) and the parked position 42.

[0046] While FIGS. 3-6 are meant to be illustrative of various actuation
techniques and/or mechanisms, it should be understood that the actuator
50 may employ other mechanism means to transition the wiper assembly 12
from a wiping position 40 to a parked position 42. Such means may include
the use of actuated 4 (or more)-bar linkages, a translatable wedge/ramp
that provides a lifting force to the armature, or other similar
mechanisms.

[0047] As generally illustrated in FIGS. 3-6, the controller 54 may be
responsive to an event signal 110. The event signal 110 may, for example,
be a signal generated by a user event, such as, for example, depressing a
button, toggling a switch, or turning a dial (i.e., actuation means
performed by a user/passenger of the vehicle). As such, the controller 54
may be responsive to the actuation of the button/switch/dial by the user
(and to corresponding event signal 110) to generate an electrical
actuation signal 52, which may, in turn, cause the wiper blade 18 to
transition between the wiping position 40 and the parked position 42.

[0048] In an embodiment, the event signal 110 may comprise a signal
signifying a key-off event (i.e., the vehicle being transitioned to an
"off" state, such as by transitioning an ignition-key to an "off"
position). As such, the controller 54 may provide the electrical
actuation signal 52 when the vehicle is in an "off" state. This
configuration may be a more automatic actuation than relying on a
user-driven event. As such, the controller 54 may be responsive to the
key-off event to transition the wiper blade 18 between the wiping
position 40 and the parked position 42. In a further configuration, the
controller 54 may generate the electrical actuation signal 52 when it
receives an indication of both a key-off event and a temperature
condition. As such, the wiper blade 18 may be automatically be
transitioned to the parked position 42 when the vehicle is off, and when
the temperature either falls to a point where the blade 18 is in danger
of freezing to the surface 14 or increases to a point where the blade 18
is in danger of melting/deforming on the surface 14.

[0049] While the best modes for carrying out the invention have been
described in detail, particularly with respect to FIGS. 3-6, those
familiar with the art to which this invention relates will recognize that
various alternative actuator designs may be employed. It is intended that
all matter contained in the above description or shown in the
accompanying drawings shall be interpreted as illustrative only and not
as limiting.